Firing mechanism



E. GARRETT FIRING MECHANISM Nov. 30, 1948.

2 Sheets-Sheet 1 Filed April 22, 1944 A QA/# ATTORNEY E. GARRETT FIRING MECHANISM Nav. 30,. 194s.

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EMIL @ARRL-rr ATTORNEY Patented Nov. 30, 1948 UNITED STATES orrlcr ATENT (Granted underl the act of March 3, 1883, as y amended April 30, 1928; 370 0. G. 757) This invention relates to firing mechanisms for weapons and has particular reference to a combined firing and recoil absorbing mechanism of novel construction which is particularly adapted for use in muzzle loading shoulder weapons. It is to be understood, however, that the new mechanism may be used in other types of Weapons as well.

An object of this invention is to provide a combined firing mechanism and recoil absorbing mechanism particularly adapted to a muzzle loading shoulder weapon for firing relatively large caliber ammunition. l

Another object of the invention is to provide a shoulder-iired long-range antitank or antipersonnel gun having spring means for decreasing the amount of :recoil force transmitted to the shoulder of the user.

Another'object of this invention is to'provide a weapon as described above which utilizes a standard mortar barrel and ammunition.

A further Object of this invention is to provide a device as referred to above which is light in weight,'easy to assemble and disassemble, positive in operation, and simple to manufacture and to maintain in correct adjustment.

These and other objects of the invention will be obvious from the following specification and the accompanying drawings, in which Fig. 1 is a longitudinal sectional view of a shoulder weapon embodying the invention, showing the mechanism in cocked condition ready for firing;

Fig. 2 is a View similar to Fig. 1 but showing the mechanism at `the moment of rng before recoil commences;

Fig. 3 is a View similar to Fig. 1 but showing the` mechanism at the end Aof therecoil movement before the beginning` of counterrecoil with the piston turned 45 from the section shown in Fig, 1, and

Figs. 4, 5, 6 and '1 `are `cross-sectional views taken on lines 4 4, 5 5, 6 6 and 1 1, respectively, of Fig. 1. i

' In the drawings, a gun barrel housing or other such ammunition containing means I is threaded at its rear end to receive a closure I I which has a rearwardly' extending axial hub I2 and an axial passage I3 which is narrowed at its forward endv `ently. The closure has a forwardly extending.

thickened portion I5 against which a projectile is adaptedto rest when the'gun is loaded.` A' percussion firing pin I1 having an enlarged base I8.;

- and a narrow forward portion I9 is mounted in the axial passage I3 in the cap and `is normally maintained out of engagement with the base of the projectile by means of a spring which surrounds the firing pin. Shoulder Ila on the pin contacts shoulder` I4 to define the limit of forward movement of the ring pin, the firing pin being retained in the cap by suitable ldetent means (not shown). A firing pin housing 2I is threaded onto the hub I2 and encloses the spring 20.

The outer surface of the barrel is smooth and is mounted for longitudinal movement in a slide 22 to the rear end of which is threaded one end of a cylinder 23 which is closed and substantially sealed at its other end by a plug 24 carrying a butt plate 25. A shoulder 26 is provided at the rear end of the slide 22 in order to engage the shoulder 21 on the cap II for a purpose which will be described presently.

Slidably mounted in the cylinder 23 is a piston 28 provided with an axial boss 29 extending forwardly in axial alignment with the enlarged head I8 of firing pin I1 forming a striker therefor. The piston 28 'has a rearwardly extending hollow cylindrical portion 3l! having an outer diameter somewhat smaller than the inner diameter of the cylinder 23. A piston washer 3| and packing 32 surround the cylindrical portion 30' and are maintained in place thereon by a washer nut 33 whichV is threaded to the rear end of the hollow cylin` drical portion 30 and is of approximately the same outer diameter as the piston 28, thus forming a rear bearing surface for the piston assembly. Theuse of the packing 32 results in a substantially airtight `iit of the piston in the cylinder. That is, while substantially airtight, the t of the pistonl in the cylinder permits a slow rate of air leakage around the piston into the rear end of the cylinder 23 after theweapon is fired, thus retarding return of the piston to the position shown in Fig. 1 as will be discussed presently.

' The piston head '28 is provided with a plurality of openings 34, as `shown in Figs. 3, 5 and 6. An annular valve washer. 35 is mounted on the boss 29 and extends `outwardly in a radial direction so as to cover the openings 3d in the piston head. A

plurality ofvalve washer guides 36 are mountedv in the piston head 28 and extend forwardly therefrom through openings in the valve washer 35. Acoil spring31 surrounds each of the guides 36,

bearing against the enlarged head of the guide- 3B and againstthe valve washer 35 so as to bias the valve washer towards engagement with the front surface of the piston head 28 to closeV openings 34.

A short, heavy buffer spring 38 is mounted in the rear end of the cylinder 23 on the plug 24 for cushioning the recoil of the weapon, as will be explained presently. A smaller coiled spring 39, called the recoil spring, bears at one end against the plug .2d andat the other end-,extends through the washer nut 33 and bears against the rear surface of the piston head 28 so as to urge the piston head forwardly. A coiled separator spring 4l) is tightly mounted around the firing pin housing 2l at its forward end so as to bear against the base of closure Il. The rear end of spring 40 bears against the valve washer '35, tending to separate piston 28 from the base 'of l,the barrel.

A pair of spaced L-shaped guides i is attached to the lower side of the cylinder 23 so as to form a slideway closed at the front end by :stop 42 :attached to the underside of the cylinder andiopen at its rear end. A trigger group housing 42a comprising a hand grip .43.and trigger ,guard M is :mounted by means of outwardly extending sliding .lugs 45a in theslideway formed .by .guides 14|. rlhe .trigger group .housing is adaptedtoslide into place in members ll from the open rear end of the :slideway until ithe forward `portion of the housing 1520, :abuts stop 52, -at which point ,the spring-pressed pivoted pawl 4i5 .mounted ron ythe rea-rend ofthe trigger group housing latches into a notch Att (on the lower side of the cylinder 23, latching :the -housing .in place.

The trigger group comprises a mechanism for moving aseard loutof the path of .the piston :'28, the sear being pivotally mounted inthe .trigger group :housing and being fbiased :upwardly by a spring 48 toward -its 'retaining ,position in 'which it :is shown in Fig. l. The underside of the rear endzof the fsear forms a hook-.shaped .tongue .49 which is adapted to be vengaged "by Aa similarly shaped `upper end 'of disconnector 50 Awhich :is pivoted atits lower end 'to-a forwardly :extending arm '.51 mounted .on :the 4pivoted trigger 512. A spring l(not shown) is provided Afor :urging fthe upperend of disconnector 5l) vforwardly into engagement with sear 41, and a spring Airis :attached at ,one end to :a'projection :.54 extending inwardly from the 'trigger group housing, and at the other end Eto a rearwardly extending ftongue 55 on the disconnectorki so as tobias disoonnector upwardly 'to .the position .in which 'fit .is .shown in Fig. 1, .pulling :upwardly on the llower-end o'f'the disconneotor. A :disconnector set screw 256 fis threaded `1into the .triggerrgroup housing abovefthe trigger guard sofasrto vdeiirie-'a limit-of downward movementof the disconnector-Ell and to disengage the'sear ffromrthe disoonnector by aicamm'ing action fon lalorwardly Vextending shoulder 51 onlthe disconneotor when fthe v'trigger has lbeen .moved far kenough Vto'move the sear out of 'the path of the `*piston 228. AIn forder lto provide :a safety for the gun, a lever 58 mounted on 'the outside of the trigger housing is connected to 'a rotatable kkrod 59 lwhich extends through Athe itriggerrgrouphousing just .under the sear .41. The :rodig ih as a fllat side and lismoun'ted` so 'as Ato obstruct vdpv'vnward movement 'of thesear except when the flat side of the .rodis rotated'upwardly adjacent to the bo'ttomsurface of the sear.

'In zoperation, .the .gun uses :ammunition of the trench mortar type in which the propellant eX- plosive .iscontained in thebase fof the projectile, no :cartridge Vcase ibeing'used. The lgun 'is manually cocked'forltherst shot by .pressing thelbarrel inwardly in itheoylinder' luntil vthe piston 28 is moved rearwardly from its uncooked :position shown in Fig. 2 to the cocked position shown in Fig. 1 in which the piston is held by sear 41' against the pressure of spring 39. The pressure on the barrel is then released, whereupon the .barrel is moved forwardly into battery by the action of the spring 40. Forward movement of the barrel ceases when kthe .forward shoulder 21 on the closure Il contacts the shoulder 26 on slide 22. A projectile diagrammatically shown at i6 is slid into the muzzle until it rests against the cap Il with its detonator adjacent to the opening yi3 in the cap through which firing pin I9 is forced .as will be described presently.

With the gun cocked and loaded, the butt plate 25 is `held'against lthe shoulder of the gunner and the Weapon is aimed at the target by suitable sighting means (not shown). In order to re the gun, the safety 58 :must be moved to the re .position-.in which the at side of rod 5S faces the bottom surface of the sear. When trigger 52 is moved rearwardly, V'trigger arm .5i and ydisconnector .50 are moved downwardly against .the resistanceof springs 53 and -ll-. Downward movement of the fdisoonnector .50 .moves .the Ir-ear .end .of .the sear 4,1 `.downwardly `so .that it no longer retains piston .28 in the cocked-position, thus vallowing .the piston .2.815,0 be moved forward-1y .b y spring .39 to re the gun as will be described presently.

Disconnector .50 Vmoves v.downwardly until `the angular shoulder 5:1 -on .its 'forward edge ,strikes the end :of set screw '56 at lwhich time a -camming action causes the disconnectorto pivot rearwardly to the position shown in Fig. lseparating the disconnector from ,fthe 1tongue f4.9 of the sear and allowing spring to ,move the searupwardly to :its retaining position shown in Fig. l1. The piston "28 .and packing 3-2, which 'obstruct upward movement of sear 41 in Fig. 2, 4are 4moved rearwardly by recoil of ythe lgun lbarrel so that, as shownin AFig..3 there isnoobst-ruction to vupward movement tof :the saar. The 'release lof pressure on iiihe 'trigger 52 :allows .spring y53 to return the disconnector and trigger 'to their loriginal positions, ithe .linkage ybeing vso vpivoted lthat the disconneotor .moves forwardly and Aagain kbecomes hooked with the tongue '4:9 lof the scar. By 'this arrangement, no matter how :long the 'trigger zis held vby 'the :gunnen .the sear .always ,swings :back into retaining position in time to catch and-retain piston 128 in rits cocked 'position when the :piston moves .forwardly .upon ycounter recoil, .as will 'be described presently. "The spring :53 also assur-.es

that :upon release =o the trigger, `:the linkages become @peratively iin'terconnected so vthat movement of the trigger moves Vthe sear to re the gun.

=Wh en the sear 111 is moved :downwardly by pressure .on 'the Itrigger Aas described above, the piston .2:8 `is ffreed from fthe `de'terit :action y'of the scar and vis moved `f'rowardly by spring 39 un'til it strikes the enlarged base l 8 of the firing .pin l11 and drives :the :same .forwardly into ering :engagement fwith the .detonator on-the rear of the A'pro-- jectile. When the projectile is fired trom "the gun, the recoil forces drive .the 'barrel and fthe o pants 'mounted .on vthe rear xend thereof rearwardly, Athe piston 28 and *the parts :mounted thereon :moving 4with `the barrel. The :recoiling parts :are opposed first `by spring 39 and, upon further movement, by 'spring 38, yas shown 2in Fig. 3. fCompressionof the 4air entrapped inthe cylinder Vbehind Athe :piston 228 causes :the valve washer 35to :open against the .pressure of springs 29, 'as shown inlig. permitting the-air to-escape intothe forward endof the cylinder-which is open to the atmosphere.

When the force of recoil has been absorbed by springs 39 and 38, the pistoni, and barrel are counterrecoiled by these same springs, the piston and barrel being moved forwardly toward their original positions.A During Athis counterrecoil movement, the air within the cylinder 23 behind the piston is under reduced pressure, and springs 31 move valve washer 35 into contact with the forward surface of piston 23,'substa`ntially closing the openings 34 and causing a pneumatic bufling of thev counterrecoil motion. The slow leakage of air around piston 28 into the rear end of cylinder 23 permits -a slow return of the barrel to battery and preventsthebarrel from being forced into battery too suddenly with lthe resulting deterioration of themechanism and jolt to the gunner.` The piston Vand barrel are moved forwardly in counterrecoil by springs 39 and 38 until lthe piston 28 strikes the sear 41, which has been returned to its original retaining position by spring 48 as described above. At this point, the piston 28 is halted in its forward movement while the barrel I istmoved by spring 40 until it reaches the battery position described above. The gun is in cocked condition and is ready for reloading Aand ring. Manual cooking of the gun is necessary only before the firing of the rst shot in case the piston is in its 'extreme forward position, the gun being automatically cocked after each shot as described above. With a gun madein accordance with my invention, a t0 mm.l

While the preferred form ofthe inventionihasl been illustrated and described, it is to be understood that other variations and modifications may be made withoutdeparting from the scope ofthe invention as defined `by the appended claims.

The invention herein described may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment `of any royalties thereon or therefor.

I claim:

l. In a firearm having a slide and a barrel reciprocably mounted in said slide for receiving a projectile, the combination of a firing pin mounted in the rear end of the barrel, means for biasing the pin toward a nonring position, a striker biased toward iring engagement with said ring pin, said striker being movable independently of the barrel but being movable rearwardly by said barrel on recoil of the barrel, biasing means maintaining said striker and said barrel separated and retaining said barrel in battery when said striker isheld in cocked position, a detent for locking said striker in cocked position separated from said pin, and means for moving said detent to an inoperative position to release the striker.

2. In a firearm having a slide and a barrel reciprocably, mounted in said slide for receiving a projectile, the combination of iring means carried by the rear end of the barrel, a striker for operating said firing means, means for biasing said striker forwardly toward contact with said firing' means, detent means for maintaining said striker in cocked position and movable to release said striker for forward movement under the inuence of said rst named biasing means to re the gun, and biasing means between said striker and said barrel for maintaining the barrel in battery position when the striker is held by the detent'means, said last biasing means exerting a smaller force than the rst biasing means.

`3. In a muzzle loading firearm having a slide and a barrel reciprocably mounted in the slidefor `receiving a projectile, the combination of a cylinder closed at one end and attached at the other end tothe slide to enclose the rear end of the barrel, a piston slidably mounted in the cylinder, firing means mounted on the rear end of the barrel and operable by said piston, resilient means mounted in said cylinder for biasing the piston toward ring engagement with said firing means and for resisting recoil movenient of said piston and barrel, a movable detent normally retaining said piston in cocked position wherein said resilient means is under tension, resilient means mounted between said piston and the barrel for maintaining the barrel in firing position separated from the piston when the pistonis in cocked position, said last resilient means beingweaker than the rst resilient means, and means for moving said detent to an inoperative position to re the gun.

4. In a muzzle loading rearm having a slide and a barrel reciprocably mounted in the slide for receiving' a projectile, the combination of. a firing pin mounted in the rear end of the barrel, means for biasing the pin toward a nonring position. a striker biased toward firing engagement with said firing pin, said striker being movable independently of the barrel but being movable by said barrel on recoil of the barrel, a coiled spring mounted between said barrel and said striker for maintaining the barrel separated from the striker and for retaining said barrel in battery'when said striker is held in cocked position, a detent for locking said striker in cocked position, and means for moving said detent to an inoperative position to release the striker. U

5. In a muzzle loading firearm having a slide and a barrel reciprocably mounted in the slide for receiving -a projectile, a cylinder closed at one end and attached at the other end to the slide to enclose the rear end of the barrel, a piston slidably mounted in the cylinder, said piston having a rearwardly extending tubular portion, packing surrounding said portion, a washer -nut mounted on the rear end of said tubular portion for holding said packing in place, ring means -mounted on the rear 'end of the barrel and operable by the piston, resilient means mounted in said cylinder for biasing the piston toward` firing engagement with said ring means and for resisting recoil movement of said piston and barrel, a movable detent normally retaining said piston in cocked position wherein said resilient means is under tension, resilient means mounted between said piston and the barrel for maintaining the barrel in firing position separated from the piston when the piston is in cocked position, said last resilient means being weaker than the rst resilient means, and means for moving said detent to an inoperative position to fire the gun.

6. In a muzzle loading rearm, a slide, a barrel reciprocably mounted in the slide for receiving a projectile, a cylinder closed at one end and attached `at the other `end to the :slide to 1enclose the'rear end of the barrel, a packed piston slidably mounted'in thecylinder with a substantially airtight fit, a longitudinal -opening extending through said piston, spring-pressed means closing said opening and movable to uncover said opening on rearward movement of the piston, ringfmeans mounted .on the rear-endoi the barrel and operable by saidpiston, resilient means mounted in said cylinder for biasing the piston toward firing .engagement with said iiring means and for resisting recoil movement of said piston and barrel, a movable detent normally retaining said piston in cocked position wherein said resilient means is under tension, resilient means mounted between sad vpiston and the :barrel for maintaining the barrel in :tiring position separated from the piston whenthe piston is in-cocked position, said last resilient means being weaker thanthe'rst resilient means, andmeans for moving said detentto an inoperative position to rire the gun.

4'1. In a muzzle loading -rearm, a slide, a bar-- relirecipiocably mounted inthe slide-for receiving a projectile, a'cylinder closed .at one vend and attached at theo'ther end to -the slide toenclose the rea-rend :of the barrel, a Ypiston mounted in the cylinder, said piston having a lhollow rear portion, ring 'means 'mounted on the rear end of the @barrel and operable by said piston, a relatively strong coiled .spring in said cylinder behind the piston, one end of the spring bearing against the closed rear end of the cylinder, the other end of the spring extending into the hollow rear portion of the piston so as to urge said'piston forwardly toward ring engagement with said firing means and to resist recoil movement of said piston and barrel, 'a 'movable detent normally retaining said piston in cockedposition wherein said resilient means is under tension, resilient means mounted between said pistonand thebarrelfor maintaining the barrel in firing position separated from the :piston when the piston is in cocked position, said :last resilient Imeans lbeing weaker than the iirst resilient means, and means for'moving 4said detent to an inoperative .position to fire 'the gun.

8. A mortar comprising a tubular casing, movable means withinsaidscasing for containing am munition sin a firing Yposition,a closure `at .the .end of said containing vmeans juxtaposed 'tosaid ammunition, said closure having a spring biased .percussion firing means therein, a .spring driven striker for said iiring means, and spring .means mounted between said striker .and said closure for maintaining said firing means in an impact receiving .position with respect to said-striker.

.9. A mortar comprising a tubular casing, a housing movable within' said .casing for containing fammunition in a v:firing position, a yclosure at 'the end of said casing `juxtaposed to saidammunition, said `closure vhaving a spring :biased percussion ring .means therein, a striker for said iiring means, acoil springfor driving said striker within said casing from a iirst Atoa second position, releasable -means maintaining Asaid striker in said rst-position'and spring means positioned between said -strikerfand closure for maintaining said firing means displaced from said striker adjacent lsaid second position.

EMIL GARRETT.

'REFERENCES .CITED The vfollowing references are 0f record Iin the 171e of this patent:

UNITED .STATES l'.|`.:ATENTS FOREIGN PATENTS 'Country Date Great Britain 1910 yGreat Britain Apr. 3,1919 France Nov. -20, 1919 Germany J'une 2, 1920 Number Number 

